Commencal meta

Commencal has a few wicked deals on their website. One is the metal v4.2 brushed aluminium frame. It's only available in medium....I'm 184cm tall and this would generally probably ride a large. I'm coming from a 2014 medium intense tracer that felt fine to me and has much smaller reach numbers than this meta.

How much should I pay attention to sizing charts? also I'm not going to be able to sit on a meta before I order (I have before, and they re nice).